Description of problem:
Yelp can't open open html files specified by path - eq. "yelp foo.html".
In such case yelp either shows a blank window or "URL cannot be shown".

Sometimes it also starts printing some memory related information while still not showing only a blank window:

Memory pressure relief: Empty the PageCache: =dirty (at 2224353280 bytes)
Memory pressure relief: Prune MemoryCache live resources: =dirty (at 2224353280 bytes)
Memory pressure relief: Drain CSSValuePool: =dirty (at 2224353280 bytes)
Memory pressure relief: Discard StyleResolvers: =dirty (at 2224353280 bytes)
Memory pressure relief: Discard all JIT-compiled code: +dirty 8392704 bytes (from 2224353280 to 2232745984)
Memory pressure relief: Dropping buffered data from paused media elements: +dirty 67121152 bytes (from 2232745984 to 2299867136)
Memory pressure relief: Purge inactive FontData: =dirty (at 2526408704 bytes)
Memory pressure relief: Clear WidthCaches: =dirty (at 2526408704 bytes)
Memory pressure relief: Discard Selector Query Cache: =dirty (at 2526408704 bytes)
Memory pressure relief: Prune MemoryCache dead resources: =dirty (at 2526408704 bytes)
Memory pressure relief: Prune presentation attribute cache: =dirty (at 2526408704 bytes)
Memory pressure relief: Run malloc_trim: -dirty 24576 bytes (from 2526408704 to 2526384128)
Memory pressure relief: Release free FastMalloc memory: =dirty (at 2526384128 bytes)
Memory pressure relief: Empty the PageCache: =dirty (at 2526384128 bytes)
Memory pressure relief: Prune MemoryCache live resources: =dirty (at 2526384128 bytes)
Memory pressure relief: Drain CSSValuePool: =dirty (at 2526384128 bytes)


Version-Release number of selected component (if applicable):
yelp 3.20.1

How reproducible:
Always.

Steps to Reproduce:
1. prepare a html file:
echo "hello world" > test.html

2. try to show it with yelp:
yelp test.html

Actual results:
Blank window or "URL cannot be shown".

Expected results:
Yelp renders the html file.

Additional info:
This used to work before - we use html files as fallback in the Anaconda built in help system when no content is available for a given screen. Yelp used to be able to show them but can no longer do that.

The DocBook xml files we use for the actual help content are on the other hand opened and shown normally.